Non-contact charging module and reception-side and transmission-side non-contact charging apparatuses using the same

ABSTRACT

It is an object to provide a non-contact charging module that prevents the magnet from negatively influencing particularly the inside portion of a coil and improves power transmission efficiency, even when a magnet is used for alignment. This non-contact charging module is a reception-side non-contact charging module, to which power is transmitted from a transmission-side non-contact charging module which is equipped with magnet, by electromagnetic induction, in which the non-contact charging module includes a planar coil portion around which spiral electric lines are wound, and a magnetic sheet disposed to face the surface of coil of the planar coil portion so that it faces the magnet of the transmission-side contact module, in which the inner diameter of the planar coil portion is larger than the magnet.

TECHNICAL FIELD

The present invention relates to a non-contact charging module that hasa planar coil portion made of spiral electrical lines and a magneticsheet and a reception-side and transmission-side non-contact chargingapparatuses using the same.

BACKGROUND ART

In recent years, apparatuses that can charge a body apparatus in anon-contact type using a charger are widely used. In the apparatuses, atransmission-side non-contact charging module is disposed on the side ofthe charger, a reception-side non-contact charging module is disposed onthe side of the body apparatus, and electromagnetic induction isgenerated between the modules to supply power from the side of thecharger to the side of the body apparatus. In addition, it is suggestedto apply a portable terminal apparatus as the body apparatus.

It is demanded to decrease the thickness and the size of the bodyapparatus or the charger of this portable terminal apparatus. In orderto meet the demand, it is considered to include a planar coil portionfunctioning as the transmission-side non-contact charging module or thereception-side non-contact charging module, and a magnetic sheet (referto Patent Literature 1).

CITATION LIST Patent Literature

-   PTL 1-   Japanese Patent Application Laid-Open No. 2006-42519

SUMMARY OF INVENTION Technical Problem

In this type of non-contact charging module, the position of aprimary-side non-contact charging module (transmission-side non-contactcharging module) and the position of a secondary-side non-contactcharging module (reception-side non-contact charging module) need to beaccurately aligned. This is to efficiently perform the electromagneticinduction to transmit power.

A method using a magnet is known as one method that accurately alignsthe position of the primary-side non-contact charging module(transmission-side non-contact charging module) and the position of thesecondary-side non-contact charging module (reception-side non-contactcharging module). This method is a method in which the magnet is mountedto at least one of the primary-side non-contact charging module and thesecondary-side non-contact charging module, the magnets of both sides orone magnet and the other magnetic sheet attract each other, andtherefore aligning is performed.

A method that performs aligning without using the magnet is known asanother method that accurately aligns the position of the primary-sidenon-contact charging module and the position of the secondary-sidenon-contact charging module.

For example, this is a method in which a convex portion is formed in acharging surface of a charger mounted with the primary-side non-contactcharging module, a concave portion is formed in an electronic apparatusmounted with the secondary-side non-contact charging module, the convexportion are fitted in the concave portion, and compulsory aligning ofthe primary-side non-contact charging module and the secondary-sidenon-contact charging module is physically (geometrically) performed.This is a method in which the primary-side non-contact charging moduledetects the position of a coil of the secondary-side non-contactcharging module in order to automatically move the position of the coilof the primary-side non-contact charging module to the position of acoil of the secondary-side non-contact charging module. This is a methodin which a plurality of coils are provided in the charger such that aportable apparatus is chargeable in all places of a charging surface ofthe charger.

However, in the case where the magnet is used in aligning of theprimary-side non-contact charging module and the secondary-sidenon-contact charging module and the case where the magnet is not used,an L value of the coil that is provided in each non-contact chargingmodule significantly changes. In the electromagnetic induction to supplypower, the resonance frequency is determined using the L value of thecoil that is provided in each non-contact charging module.

For this reason, in the case where the magnet is used in aligning of theprimary-side non-contact charging module and the secondary-sidenon-contact charging module and the case where the magnets is not used,there is a problem that it is difficult to commonly use the non-contactcharging module.

Therefore, in view of the above problems, it is an object of the presentinvention to provide a non-contact charging module and reception-sideand transmission-side non-contact charging apparatuses using the samethat can suppress a change in an L value of a coil provided in thenon-contact charging module in both of the case where a magnet includedin the other non-contact charging module is used when a primary-sidenon-contact charging module and a secondary-side non-contact chargingmodule are aligned and the case where the magnet is not used, and can beused in both of the case where the magnet is used and the case where themagnet is not used.

Solution to Problem

In order to solve the above problems, the present invention has afeature of providing a non-contact charging module that has a case whereusing a magnet included in a counterpart-side non-contact chargingmodule or a case where not using the magnet, when aligning with thecounterpart-side non-contact charging module, the non-contact chargingmodule includes: a planar coil portion where electrical lines are wound;and a magnetic sheet that places a coil surface of the planar coilportion and faces the coil surface of the planar coil portion, wherein asize of a hollow portion of the planar coil portion is more than a sizeof the magnet included in the counterpart-side non-contact chargingmodule.

Advantageous Effects of Invention

According to the present invention, a non-contact charging module thatdoes not change an L value of a coil provided in the non-contactcharging module in both of the case where a magnet included in acounterpart-side non-contact charging module is used and the case wherethe magnet is not used when the primary-side non-contact charging moduleand the secondary-side non-contact charging module are aligned, so thatit is possible to provide a non-contact charging module that can performefficient aligning and power transmission in both of the case where themagnet is used and the case where the magnet is not used.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a non-contact power transmittingapparatus according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating the configuration of a non-contactcharger according to the embodiment of the present invention;

FIG. 3 is a diagram illustrating a primary-side non-contact chargingmodule according to the embodiment of the present invention;

FIG. 4 is a detailed diagram illustrating the primary-side non-contactcharging module according to the embodiment of the present invention;

FIG. 5 is a diagram illustrating the configuration of a portableterminal apparatus according to the embodiment of the present invention;

FIG. 6 is a diagram illustrating a secondary-side non-contact chargingmodule according to the embodiment of the present invention;

FIG. 7 is a detailed diagram illustrating the secondary-side non-contactcharging module according to the embodiment of the present invention;

FIG. 8 is a diagram illustrating a relation of the primary-sidenon-contact charging module including a magnet and the secondary-sidenon-contact charging module;

FIG. 9 is a diagram illustrating a relation of the inner diameter of thecoil and an L value of the coil;

FIG. 10 is a schematic diagram illustrating a position relation of anon-contact charging module according to the embodiment of the presentinvention and the magnet included in the other non-contact chargingmodule performing power transmission;

FIG. 11 is a diagram illustrating a decrease ratio of the L value of theplanar coil portion in the case where the magnet is included withrespect to the case where the magnet is not included, when changing adimension of a diagonal line of the inner side of a rectangular planarcoil portion and a dimension of the inner diameter of a circular planarcoil portion in FIG. 10;

FIG. 12 is a diagram illustrating the magnitude of the magnetic fieldthat is generated by the rectangular planar coil portion; and

FIG. 13 is a diagram illustrating a result that is obtained by measuringthe L value of the planar coil portion by changing the thickness of amagnetic sheet according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

In the invention according to Claim 1, a transmission-side non-contactcharging module transmits power to a reception-side non-contact chargingmodule by electromagnetic induction. The transmission-side non-contactcharging module can perform aligning with the reception-side non-contactcharging module by a first section performing aligning by using a magnetincluded in the reception-side non-contact charging module when aligningwith the reception-side non-contact charging module is performed and asecond section performing aligning by not using the magnet. Thetransmission-side non-contact charging module includes a planar coilportion where electrical lines are wound, a terminal that supplies acurrent from an external power supply to the planar coil portion, and amagnetic sheet that places a coil surface of the planar coil portion andfaces the coil surface of the planar coil portion. A size of a hollowportion of the planar coil portion is more than a size of the magnetincluded in the reception-side non-contact charging module. Thereby, atransmission-side non-contact charging module and a transmission-sidenon-contact charging apparatus using the same that do not change an Lvalue of a coil provided in the transmission-side non-contact chargingmodule in both of the case where the magnet included in thereception-side non-contact charging module is used when a primary-sidenon-contact charging module and a secondary-side non-contact chargingmodule are aligned and the case where the magnet is not used and can beused in both of the case where the magnet is used and the case where themagnet is not used can be configured.

In the invention according to Claim 2, the distance of an end of ahollow portion of the planar coil portion and an outer end of the magnetis larger than 0 mm and smaller than 6 mm. Thereby, the L values in thecase where magnet 30 a is used and the case where magnet 30 a is notused can be set to be similar to each other while the L values aremaintained at 15 μH or more.

In the invention according to Claim 3, the planar coil portion isconfigured such that an area of the magnet becomes 80 to 95% of an areaof an inner circle of the planar coil portion, in a surface parallel tothe planar coil portion. Thereby, the variation in the aligningprecision can be resolved and the aligning precision of the primary-sidenon-contact charging module and the secondary-side non-contact chargingmodule can be improved.

In the invention according to Claim 4, an area of the hollow portion ofthe coil portion is larger than an area of a circle having the diameterof 15.5 mm. Thereby, a transmission-side non-contact charging module anda transmission-side non-contact charging apparatus using the same thatcan be used in both of the case where a magnet is used and the casewhere a magnet is not used can be configured to any kind of magnet.

In the invention according to Claim 5, a transmission-side non-contactcharging apparatus includes the planar coil portion that is included inthe non-contact charging module according to any one of claims 1 to 4.Thereby, an L value of a coil provided in the transmission-sidenon-contact charging module is not changed in both of the case where themagnet is used when the transmission-side non-contact charging moduleand the reception-side non-contact charging module are aligned and thecase where the magnet is not used. Therefore, the non-contact chargingmodule can be used in both of the case where the magnet is used and thecase where the magnet is not used.

In the invention according to Claim 6, the electrical lines of theplanar coil are wound in a rectangular shape. Thereby, the distance ofthe counterpart-side magnet and the coil portion at each corner can beincreased and an influence of the magnet can be suppressed.

Embodiment

Now, an embodiment of the present invention will be described in detailwith reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a non-contact power transmittingapparatus according to an embodiment of the present invention.

The non-contact power transmitting apparatus includes primary-sidenon-contact charging module 1 (transmission-side non-contact chargingmodule) and secondary-side non-contact charging module 2 (reception-sidenon-contact charging module) and transmits power from primary-sidenon-contact charging module 1 to secondary-side non-contact chargingmodule 2 using an electromagnetic induction action. The non-contactpower transmitting apparatus is used in transmitting power of about 5 Wor less. The frequency of power transmission is about 110 to 205 kHz.Primary-side non-contact charging module 1 is mounted to a charger andsecondary-side non-contact charging module 2 is mounted to, for example,a mobile phone, a digital camera, and a PC.

Primary-side non-contact charging module 1 includes primary-side coil 11a, magnetic sheet 3, resonance capacitor (not illustrated), and powerinput section 5. Power input section 5 is connected to commercial powersupply 300 functioning as an external power supply, receives power ofabout 100 to 240 V, converts the power into a predetermined current(direct current 12 V, 1 A), and supplies the predetermined current toprimary-side coil 11 a. Primary-side coil 11 a generates a magneticfield according to the shape thereof, the winding number thereof, andthe supplied current. The resonance capacitor is connected toprimary-side coil 11 a and determines the resonance frequency of themagnetic field generated from primary-side coil 11 a according to arelation with primary-side coil 11 a. The electromagnetic inductionaction from primary-side non-contact charging module 1 to secondary-sidenon-contact charging module 2 is performed by the resonance frequency.

Meanwhile, secondary-side non-contact charging module 2 includessecondary-side coil 11 b, magnetic sheet 4, resonance capacitor (notillustrated), rectifying circuit 6, and power output section 7.Secondary-side coil 11 b receives the magnetic field generated fromprimary-side coil 11 a, converts the magnetic field into a predeterminedcurrent by the electromagnetic induction action, and outputs thepredetermined current to the outside of secondary-side non-contactcharging module 2 through rectifying circuit 6 and power output section7. Rectifying circuit 6 rectifies the predetermined current which is analternating current and converts the predetermined current into apredetermined current which is a direct current (direct current 5 V, 1.5A). Power output section 7 is an external output section ofsecondary-side non-contact charging module 2 and supplies power toelectronic apparatus 200 connected to secondary-side non-contactcharging module 2 through power output section 7.

Next, the case where primary-side non-contact charging module 1 ismounted to a non-contact charger will be described.

FIG. 2 is a diagram illustrating the configuration of a non-contactcharger according to the embodiment of the present invention. An innerportion of the non-contact charger illustrated in FIG. 2 can be viewed.

Non-contact charger 400 that transmits power using the electromagneticinduction action has primary-side non-contact charging module 1 in acase constituting an exterior package.

Non-contact charger 400 has plug 401 that is plugged into outlet 301 ofcommercial power supply 300 disposed indoors or outdoors. By pluggingplug 401 into outlet 301, non-contact charger 400 can receive power fromcommercial power supply 300.

Non-contact charger 400 is disposed on desk 501 and primary-sidenon-contact charging module 1 is disposed in the vicinity of surface 402of the side opposite to the side of a desk surface of non-contactcharger 400. A principal surface of primary-side coil 11 a inprimary-side non-contact charging module 1 is disposed in parallel tosurface 402 of the side opposite to the side of the desk surface ofnon-contact charger 400. In this way, a power reception work area of theelectronic apparatus mounted with secondary-side non-contact chargingmodule 2 can be secured. Non-contact charger 400 may be disposed on awall surface. In this case, non-contact charger 400 is disposed in thevicinity of a surface of the side opposite to the side of the wallsurface.

Primary-side non-contact charging module 1 may have magnet 30 a that isused in aligning with secondary-side non-contact charging module 2. Inthis case, magnet 30 a is disposed in a hollow portion that ispositioned at a center area of primary-side coil 11 a.

Next, primary-side non-contact charging module 1 will be described.

FIG. 3 is a diagram illustrating the primary-side non-contact chargingmodule according to the embodiment of the present invention andillustrating the case where the primary-side coil is circular. ThoughFIG. 3 illustrates the primary-side coil that is a circular coil that iswound in a circular shape, the primary-side coil may be a rectangularcoil that is wound in a substantially rectangular shape. The specificconfiguration of the primary-side non-contact charging module describedhereinafter is basically applied to the secondary-side non-contactcharging module. The difference of the primary-side non-contact chargingmodule and the secondary-side non-contact charging module will bedescribed in detail below.

Primary-side non-contact charging module 1 includes primary-side coil 11a where electrical lines are wound in a spiral shape and magnetic sheet3 that is provided to face a surface of primary-side coil 11 a.

As illustrated in FIG. 3, primary-side coil 11 a includes a coil that iswound around a conductor in a radial direction to draw a whirlpool onthe surface and terminals 22 a and 23 a that function as currentsupplying sections provided on both ends of the coil. That is, terminals22 a and 23 a that function as the current Supplying sections suppliesthe current from commercial power supply 300 which is the external powersupply to primary-side coil 11 a. The coil is obtained by windingelectrical lines in parallel on the plane and a surface that is formedby the coil is called a coil surface. The thickness direction is a stackdirection of primary-side coil 11 a and magnetic sheet 3.

Magnetic sheet 3 includes flat portion 31 a that places primary-sidecoil 11 a, center portion 32 a that is a center portion of flat portion31 a and corresponds to a hollow area of primary-side coil 11 a, andlinear concave portion 33 a that inserts a part of a leading line ofprimary-side coil 11 a. In center portion 32 a, a concave portion or athrough-hole is formed with respect to flat portion 31 a.

In primary-side non-contact charging module 1 according to the presentembodiment, primary-side coil 11 a is wound from an inner diameter wherea diameter is 20 mm to the outside and an outer diameter of theprimary-side coil becomes 30 mm. That is, primary-side coil 11 a iswound in a doughnut shape. Primary-side coil 11 a may be wound in acircular shape and may be wound in a polygonal shape.

By wounding the electrical lines to leave a space, the floating capacitybetween the electrical line of an upper stage and the electrical line ofa lower stage decreases and alternating-current resistance ofprimary-side coil 11 a can be suppressed to a minimum. In addition, thethickness of primary-side coil 11 a can be suppressed by wounding theelectrical lines densely.

Primary-side non-contact charging module 1 may have magnet 30 a that isused in aligning with secondary-side non-contact charging module 2. Inthis case, a shape of magnet 30 a is defined to a circular shape and adiameter thereof is defined to 15.5 mm or less by the standard (WPC).Magnet 30 a has a coin shape and needs to be disposed such that a centerthereof is matched with a winding center axis of primary-side coil 11 a.This is to decrease an influence of magnet 30 a with respect toprimary-side coil 11 a.

That is, as an aligning method, the following methods are used. Forexample, a method in which a convex portion is formed in a chargingsurface of a charger, a concave portion is formed in an electronicapparatus of the secondary side, the convex portion is fitted into theconcave portion, and compulsory aligning is physically (geometrically)performed is used. A method in which a magnet is mounted to at least oneof the primary side and the secondary side, the magnets of both sides orone magnet and the other magnetic sheet attract each other, and aligningis performed is used. A method in which the primary side detects theposition of a coil of the secondary side to automatically move a coil ofthe primary side to the position of the coil of the secondary side isused. A method in which a plurality of coils are provided in a chargersuch that a portable apparatus is chargeable in all places of a chargingsurface of the charger is used.

As such, the various methods that are used in aligning the coils of theprimary-side (charging-side) non-contact charging module and thesecondary-side (charged-side) non-contact charging module are described.However, the methods are divided into methods performed with the magnetand methods performed without the magnet. In addition, according to theprimary-side (charging-side) non-contact charging module, theprimary-side non-contact charging module is configured to be adapted toboth of the secondary-side (charged-side) non-contact charging modulewith the magnet and the secondary-side (charged-side) non-contactcharging module without the magnet, and charging can be performed,regardless of a type of the secondary-side (charged-side) non-contactcharging module. Therefore, convenience is improved. Likewise, accordingto the secondary-side (charged-side) non-contact charging module, thesecondary-side non-contact charging module is configured to be adaptedto both of the primary-side (charging-side) non-contact charging modulewith the magnet and using the magnet in aligning and the primary-side(charging-side) non-contact charging module without the magnet and notusing the magnet in aligning, and charging can be performed, regardlessof a type of the primary-side (charging-side) non-contact, chargingmodule. Therefore, convenience is improved. That is, in the non-contactcharging module that performs power transmission by the electromagneticinduction action with the other non-contact charging module which is acounterpart performing the power transmission and performs aligningusing the magnet included in the other non-contact charging module orperforms aligning without using the magnet when aligning with the othernon-contact charging module is performed, the non-contact chargingmodule needs to be configured to surely perform the power transmission.

As a first method that disposes magnet 30 a in the case whereprimary-side non-contact charging module 1 has magnet 30 a, a methodthat disposes magnet 30 a on a top surface of center portion 32 a ofmagnetic sheet 3 is known. As a second method that disposes magnet 30 a,a method that disposes magnet 30 a at the position instead of centerportion 32 a of magnetic sheet 3 is known. In the second method, sincemagnet 30 a is disposed in the hollow area of the coil, a size ofprimary-side non-contact charging module 1 can be decreased.

When the magnet is not used in aligning of primary-side non-contactcharging module 1 and secondary-side non-contact charging module 2, themagnet 30 a illustrated in FIG. 3 is not needed.

In this case, an influence of the magnet with respect to powertransmission efficiency of the non-contact charging module will bedescribed. In general, the magnet is provided in the hollow portion ofthe coil incorporated in at least one of the primary-side non-contactcharging Module and the secondary-side non-contact charging module.Thereby, the magnet and the magnet or the magnet and the magnetic sheet3 can be placed closely each other as close as possible, and, at thesame time, the primary-side coil and the secondary-side coil can beplaced closely each other. The magnet is circular. In this case, thediameter of the magnet becomes smaller than the inner width of the coil.In the present embodiment, the diameter of the magnet is about 15.5 mm(about 10 to 20 min) and the thickness thereof is about 1.5 to 2 mm. Aneodymium magnet may be used and the strength thereof may be about 75 to150 mT. In the present embodiment, since an interval of the coil of theprimary-side non-contact charging module and the coil of thesecondary-side non-contact charging module is about 2 to 5 mm,sufficient aligning can be performed by the corresponding magnet.

When the magnetic flux is generated between the primary-side coil andthe secondary-side coil to transmit power, if the magnet exists betweenthe primary-side coil and the secondary-side coil and around theprimary-side coil and the secondary-side coil, the magnetic flux extendsto avoid the magnet. The magnetic flux that passes through the magnetbecomes an eddy current or generates heat in the magnet and is lost. Ifthe magnet is disposed in the vicinity of the magnetic sheet, thepermeability of the magnetic sheet in the vicinity of the magnet may bedecreased. Therefore, magnet 30 a that is included in primary-sidenon-contact charging module 1 may decrease the L values of bothprimary-side coil 11 a and secondary-side coil 11 b. As a result,transmission efficiency between the non-contact charging modules may bedecreased.

FIG. 4 is a detailed diagram illustrating the primary-side non-contactcharging module according to the embodiment of the present invention.FIG. 4( a) is a top view of the primary-side non-contact charging moduleand FIG. 4( b) is a cross-sectional view taken along the line A-A of theprimary-side non-contact charging module in FIG. 4( a). FIG. 4( c) is across-sectional view taken along the line B-B of the primary-sidenon-contact charging module in FIG. 4( a) in the case where a linearconcave portion is provided. FIG. 4( d) is a cross-sectional view takenalong the line B-B of the primary-side non-contact charging module inFIG. 4( a) in the case where a slit is provided. FIGS. 4( a) and 4(b)illustrate the case where magnet 30 a is not included. When the magnetis included, magnet 30 a illustrated by a dotted line is included.

Primary-side coil 11 a achieves decreasing the thickness of non-contactcharger 400 mounted with primary-side non-contact charging module 1. Forthis reason, an area from a winding starting portion positioned in acenter area of primary-side coil 11 a to terminal 23 a is configured astwo stages in the thickness direction and the remaining area isconfigured as one stage. At this time, the electrical line of the upperstage and the electrical line of the lower stage are wound to leave aspace, the floating capacity between the electrical line of the upperstage and the electrical line of the lower stage decreases, and thealternating-current resistance of primary-side coil 11 a can besuppressed to a minimum.

When the electrical lines are stacked and primary-side coil 11 a isextended in the thickness direction of primary-side non-contact chargingmodule 1, the amount of current that flows to primary-side coil 11 a canbe increased by increasing the winding number of primary-side coil 11 a.When the electrical lines are stacked, if the electrical line of theupper stage and the electrical line of the lower stage are wound denselythe thickness of primary-side coil 11 a is suppressed, and the amount ofcurrent flowing to primary-side coil 11 a can be increased.

In the present embodiment, primary-side coil 11 a is formed using theelectrical lines having a circular cross-sectional shape. However, theelectrical lines that have a rectangular cross-sectional shape may beused. When the electrical lines having the circular cross-sectionalshape are used, gaps are generated between the electrical lines adjacentto each other. For this reason, the floating capacity between theelectrical lines decreases and the alternating-current resistance ofprimary-side coil 11 a can be suppressed to a minimum.

It is preferable to wind primary-side coil 11 a in one stage in thethickness direction, instead of winding primary-side coil 11 a in twostages in the thickness direction, because the alternating-currentresistance of primary-side coil 11 a decreases and transmissionefficiency can be increased. This is because the floating capacity isgenerated between the electrical line of the upper stage and theelectrical line of the lower stage, if the electrical lines are wound inthe two stages. Therefore, it is preferable to wind most of the parts ofprimary-side coil 11 a in one stage, instead of winding all of the partsof primary-side coil 11 a in two stages. By winding primary-side coil 11a in one stage, primary-side non-contact charging module 1 can be formedto have the small thickness. When a planar coil portion is configured bythe two electrical lines, the two electrical lines are electricallyconnected by solder in portions of terminals 22 a and 23 a. For thisreason, the two electrical lines may be configured as one thickelectrical line. The two electrical lines may be wound in parallel tothe coil surface and may be wound vertically to the coil surface. Thatis, when the two electrical lines are parallel to the coil surface, thetwo electrical lines are wound around the same center in a planar shapeand one electrical line is inserted into the other electrical line inthe radial direction. As such, the two electrical lines are bonded inthe portions of terminals 22 a and 23 a to function as one electricalline, and the thickness can be suppressed even though the electricallines have the same cross-sectional area. That is, the cross-sectionalarea of the electrical line where the diameter is 0.25 mm can beobtained by preparing two electrical lines where the diameter is 0.18mm. Therefore, if one electrical line where the diameter is 0.25 mm isprepared, the thickness of one turn of the coil is 0.25 mm and the widthof the coil in the radial direction is 0.25 mm. However, if twoelectrical lines where the diameter is 0.18 mm are prepared, thethickness of one turn of the coil is 0.18 mm and the width of the coilin the radial direction is 0.36 mm. The thickness direction is a stackdirection of the planar coil portion and magnetic sheet 3. Only parts ofthe center side of the coil may overlap in two stages in the thicknessdirection and the remaining part of the outside may be configured as onestage. In the case where the electrical lines are wound vertically tothe coil surface, the thickness of non-contact charging module 1increases. However, the cross-sectional area of the electrical lineincrease substantially, the amount of current that flows to the planarcoil portion can be increased, and the sufficient winding number can beeasily secured. In the present embodiment, primary-side coil 11 a isconfigured by the electrical lines having the diameter of about 0.18 to0.35 mm. In primary-side coil 11 a of primary-side non-contact chargingmodule 1, the electrical lines having the diameter of 0.25 to 0.35 mmare preferable.

The loss in primary-side coil 11 a can be prevented by decreasing thealternating-current resistance of primary-side coil 11 a and powertransmission efficiency of primary-side non-contact charging module 1that depends on the L value can be improved by improving the L value.

In the present embodiment, primary-side coil 11 a is formed in anannular shape (circular shape). A shape of primary-side coil 11 a is notlimited to the annular shape (circular shape) and may be an ellipticalshape, a rectangular shape, and a polygonal shape. If aligning ofprimary-side non-contact charging module 1 and secondary-sidenon-contact charging module 2 is considered, the shape of primary-sidecoil 11 a is preferably the annular shape (circular shape). This reasonis as follows. When the shape of primary-side coil 11 a is the annularshape (circular shape), because transmission/reception of power can beperformed over a wider range, aligning of primary-side coil 11 a ofprimary-side non-contact charging module 1 and secondary-side coil 11 bof secondary-side non-contact charging module 2 can be easily performed.That is, since transmission/reception of the power can be performed overa wider range, it is difficult that secondary-side non-contact chargingmodule 2 receives an influence of an angle with respect to primary-sidenon-contact charging module 1.

Terminals 22 a and 23 a may be placed closely each other and may beapart from each other. However, when terminals 22 a and 23 a are apartfrom each other, primary-side non-contact charging module 1 may beeasily mounted.

Magnetic sheet 3 is provided to improve power transmission efficiency ofnon-contact charging using the electromagnetic induction action, andincludes flat portion 31 a, center portion 32 a that is a center andcorresponds to an inner diameter of primary-side coil 11 a, and linearconcave portion 33 a. When magnet 30 a is provided to perform aligningof primary-side non-contact charging module 1 and secondary-sidenon-contact charging module 2, magnet 30 a may be disposed on centerportion 32 a and may be disposed at the position instead of centerportion 32 a. A concave portion or a through-hole may be provided in aportion that corresponds to the hollow portion of coil 11 a of magneticsheet 3.

As magnetic sheet 3, a ferrite sheet of the Ni—Zn system, a ferritesheet of the Mn—Zn system, and a ferrite sheet of the Mg—Zn system andthe like may be used. Magnetic sheet 3 may be configured as a singlelayer, may be configured by stacking a plurality of sheets made of thesame material in the thickness direction, and may be configured bystacking a plurality of different magnetic sheets in the thicknessdirection. Magnetic sheet 3 is preferably configured such that thepermeability is 250 or more and the saturation magnetic flux density is350 mT or more.

An amorphous metal may be used as magnetic sheet 3. When the ferritesheet is used as magnetic sheet 3, the alternating-current resistance ofprimary-side coil 11 a can be decreased, and when the amorphous metal isused as magnetic sheet, the thickness of primary-side coil 11 a can bedecreased. The shape of magnetic sheet 3 may be a circular shape, arectangular shape, a polygonal shape, and a rectangular shape and apolygonal shape having large curved lines at four corners.

Next, an influence of the magnet with respect to primary-sidenon-contact charging module 1 and secondary-side non-contact chargingmodule 2 (described later) will be described. The magnetic field that isgenerated by primary-side non-contact charging module 1 is received bysecondary-side coil 11 b in secondary-side non-contact charging module 2to transmit power. In this case, if the magnet is disposed aroundprimary-side coil 11 a and secondary-side coil 11 b, the magnetic fieldmay be generated to avoid the magnet or the magnetic field that passesthrough the magnet may be removed. The permeability of a part ofmagnetic sheet 3 that is close to the magnet may decrease. That is, themagnetic field is weakened by the magnet. Therefore, in order tominimize the magnetic field weakened by the magnet, a countermeasure isnecessary for primary-side coil 11 a and secondary-side coil 11 b to beapart from the magnet or magnetic sheet 3 that is difficult to beaffected by the magnet.

Next, the case where secondary-side non-contact charging module 2 ismounted to a portable terminal apparatus will be described.

FIG. 5 is a diagram illustrating the configuration of a portableterminal apparatus according to the embodiment of the present inventionand is a perspective view illustrating the exploded portable terminalapparatus.

Portable terminal apparatus 520 includes liquid crystal panel 521,operation button 522, substrate 523, battery pack 524 and the like.Portable terminal apparatus 520 that receives power using theelectromagnetic induction action is a portable terminal apparatus thatincludes secondary-side non-contact charging module 2 in casing 525 andcasing 526 forming an exterior package thereof.

On a back surface of casing 525 where liquid crystal panel 521 andoperation button 522 are provided, substrate 523 including a controlsection that receives information input from operation button 522,displays needed information on liquid crystal panel 521, and controlsentire portable terminal apparatus 520 is provided. In addition, on theback surface of substrate 523, battery pack 524 is provided. Batterypack 524 is connected to substrate 523 and supplies power to substrate523.

On the back surface of battery pack 524, that is, on the side of casing526, secondary-side non-contact charging module 2 is provided.Secondary-side non-contact charging module 2 receives power fromprimary-side non-contact charging module 1 by the electromagneticinduction action and charges battery pack 524 using the power.

Secondary-side non-contact charging module 2 includes secondary-sidecoil 11 b, magnetic sheet 4 and the like. When a power supply directionis set to the side of casing 526, if secondary-side coil 11 b andmagnetic sheet 4 are disposed sequentially from the side of casing 526between casing 526 and substrate 523, an influence of substrate 523 andbattery pack 524 can be alleviated and power can be received. AlthoughFIG. 5 illustrates a state in which magnetic sheet 4 is disposed closerto the side of casing 526 than secondary-side coil 11 b, FIG. 5schematically illustrates the configuration for easy understanding. Inpractice, as described above, secondary-side coil 11 b and magneticsheet 4 are disposed sequentially from the side of casing 526.

Next, secondary-side non-contact charging module 2 will be described.

FIG. 6 is a diagram illustrating the secondary-side non-contact chargingmodule according to the embodiment of the present invention andillustrating the case where the secondary-side coil is a circular coil.

FIG. 7 is a detailed diagram illustrating the secondary-side non-contactcharging module according to the embodiment of the present invention.FIG. 7( a) is a top view of the secondary-side non-contact chargingmodule and FIG. 7( b) is a cross-sectional view taken along the line C-Cof the secondary-side non-contact charging module in FIG. 7( a). FIG. 7(c) is a cross-sectional view taken along the line D-D of thesecondary-side non-contact charging module in FIG. 7( a) in the casewhere a linear concave portion is provided. FIG. 7( d) is across-sectional view taken along the line D-D of the secondary-sidenon-contact charging module in FIG. 7( a) in the case where a slit isprovided. FIGS. 7( a) and 7(b) illustrate the case where magnet 30 b isnot included. In the case where the magnet is included, magnet 30 b thatis illustrated by a dotted line is included.

FIGS. 6 and 7 that illustrate secondary-side non-contact charging module2 correspond to FIGS. 3 and 4 that illustrate primary-side non-contactcharging module 1. The configuration of secondary-side non-contactcharging module 2 is substantially the same as the configuration ofprimary-side non-contact charging module 1.

Secondary-side non-contact charging module 2 is different fromprimary-side non-contact charging module 1 in the size and the materialof magnetic sheet 4. Magnetic sheet 4 that is used in secondary-sidenon-contact charging module 2 has the size that is smaller than about40×40 mm and the thickness that is about 2 mm or less.

The size of magnetic sheet 3 that is used in primary-side non-contactcharging module 1 is different from the size of magnetic sheet 4 that isused in secondary-side non-contact charging module 2. This is becausesecondary-side non-contact charging module 2 is generally mounted to aportable electronic apparatus and reducing the size is required. In thepresent embodiment, magnetic sheet 4 is substantially square and has thesize of about 33×33 mm. It is demanded to form magnetic sheet 4 with thesize equal to or larger than the size of an outer circumferential end ofsecondary-side coil 11 b. The shape of magnetic sheet 3 may be acircular shape, a rectangular shape, a polygonal shape, and arectangular shape and a polygonal shape having large curved lines atfour corners.

Since secondary-side non-contact charging module 2 is used in a portableterminal as the reception side of power supply, an occupation space ofsecondary-side non-contact charging module 2 in the portable terminalhas no room. Since the amount of current flowing to secondary-side coil11 b of secondary-side non-contact charging module 2 is small, aninsulating property of magnetic sheet 4 is not so required. In thepresent embodiment, secondary-side coil 11 b is configured using theelectrical lines having the diameter of about 0.18 to 0.35 mm and theelectrical lines having the diameter of about 0.18 to 0.30 mm arepreferable in secondary-side coil 11 b of secondary-side non-contactcharging module 2.

When the mounted electronic apparatus is a mobile phone, thesecondary-side non-contact charging module is generally disposed betweenthe case constituting the exterior package of the mobile phone and thebattery packet positioned in the mobile phone. In general, since thebattery pack is a casing made of aluminum, the battery pack adverselyaffects power transmission. This is because the eddy current isgenerated in the aluminum in a direction weakening the magnetic fluxgenerated by the coil and the magnetic flux of the coil is weakened. Forthis reason, an influence with respect to the aluminum needs to bealleviated by providing magnetic sheet 4 between the aluminum which isthe exterior package of the battery pack and secondary-side coil 11 bdisposed on the exterior package thereof.

Next, a relation of a size of magnet 30 a and a size of the innerdiameter of primary-side coil 11 a will be described. Here, the casewhere magnet 30 a is disposed on primary-side non-contact chargingmodule 1 will be described. However, the same relation is realized inthe case where magnet 30 b is disposed on secondary-side non-contactcharging module 2. In this case, magnet 30 b corresponds to magnet 30 a.

FIG. 8 is a diagram illustrating a relation of the primary-sidenon-contact charging module including the magnet and the secondary-sidenon-contact charging module. FIG. 8( a) illustrates the case where thealigning magnet is used when the inner width of the coil is small, FIG.8( b) illustrates the case where the aligning magnet is used when theinner width of the coil is large, FIG. 8( c) illustrates the case wherethe aligning magnet is not used when the inner width of the coil issmall, and FIG. 8( d) illustrates the case where the aligning magnet isnot used when the inner width of the coil is large. In FIG. 8,primary-side non-contact charging module 1 including magnet 30 a andsecondary-side coil 11 b of secondary-side non-contact charging module 2performing power transmission are illustrated. However, the descriptionof secondary-side coil 11 b according to the relation of secondary-sidenon-contact charging module 2 described below is applied tosecondary-side non-contact charging module 2 including magnet 30 b andprimary-side coil 11 a of primary-side non-contact charging module 1performing power transmission. That is, a planar coil portion of thenon-contact charging module where aligning and power transmission can beperformed in both of the case where the other non-contact chargingmodule to be the counterpart of power transmission includes the magnetand the case where the other non-contact charging module does notinclude the magnet will be described. FIG. 9 is a diagram illustrating arelation of the inner diameter of the coil and an L value of the coil.

In the drawings, magnet 30 a is stored in only the through-hole ofprimary-side coil 11 a. However, magnet 30 a may be stored in thethrough-hole of secondary-side coil 11 b.

Primary-side coil 11 a and secondary-side coil 11 b face each other. Ininner portions 211 and 212 of coils 11 a and 11 b, the magnetic field isgenerated and power is transmitted. Inner portions 211 and 212 face eachother. Inner portions 211 and 212 are close to magnet 30 a and mayeasily receive adverse effects from magnet 30 a. That is, when themagnetic flux is generated between the primary-side coil and thesecondary-side coil to transmit power, if the magnet exists between theprimary-side coil and the secondary-side coil and around theprimary-side coil and the secondary-side coil, the magnetic flux extendsto avoid the magnet. The magnetic flux that passes through the magnetbecomes an eddy current or generates heat in the magnet, and is lost. Ifthe magnet is disposed in the vicinity of the magnetic sheet, thepermeability of the magnetic sheet in the vicinity of the magnet may bedecreased. Therefore, magnet 30 a that is included in primary-sidenon-contact charging module 1 may decrease the magnetic flux of bothprimary-side coil 11 a and secondary-side coil 11 b, particularly, innerportions 211 and 212 and may exert a bad influence. As a result,transmission efficiency between the non-contact charging modules may bedecreased. Therefore, in the case of FIG. 8( a), inner portions 211 and212 that may easily receive adverse effects from magnet 30 a mayincrease. Meanwhile, in the case of FIG. 8( c) where the magnet is notused, since the winding number of secondary-side coil 11 b is large, theL value increases. As a result, since a decrease ratio of a numericalvalue from the L value in FIG. 8( c) to the L value in FIG. 8( a) islarge, a decrease ratio of the L value may greatly increase in the casewhere magnet 30 a is included for aligning and the case where magnet 30a is not included, in the coil where the inner width is small. Asillustrated in FIG. 8( a), if the inner width of secondary-side coil 11b is smaller than the diameter of magnet 30 a, secondary-side coil 11 bmay receive adverse effects directly from magnet 30 a by an area facingmagnet 30 a. Therefore, the inner width of secondary-side coil 11 b maybe larger than the diameter of magnet 30 a.

As illustrated in FIG. 8( b), if the inner width of the coil is large,inner portions 211 and 212 that may easily receive adverse effects frommagnet 30 a greatly decrease. In the case of FIG. 8( d) where the magnetis not used, since the winding number of secondary-side coil 11 bdecreases, the L value becomes smaller than the L value in the case ofFIG. 8( c). As a result, since the decrease ratio of the numerical valuefrom the L value in FIG. 8( d) to the L value in FIG. 8( b) is small,the decrease ratio of the L value can be minimally suppressed in thecoil where the inner width is large. If the inner width ofsecondary-side coil 11 b increases, because the end of the hollowportion of coil 11 b is apart from magnet 30 a, an influence of magnet30 a can be suppressed. However, since the non-contact charging moduleis mounted to the charger or the electronic apparatus and the like, itis not possible to form the non-contact charging module larger than apredetermined size. Therefore, if the inner widths of coils 11 and 11 bare increased to decrease adverse effects from magnet 30 a, the windingnumber may decrease and the L value may decrease without depending onwhether or not the magnet exists. When magnet 30 a has a circular shape,magnet 30 a is as follows. That is, when the outer diameter of magnet 30a and the inner width of coil 11 b are almost equal to each other('outer diameter of magnet 30 a is smaller than the inner width of coil11 b by about 0 to 2 mm), magnet 30 a can be maximized, so that it ispossible to improve aligning precision of the primary-side non-contactcharging module and the secondary-side non-contact charging module.Since the inner diameter of coil 11 b can be minimized, it is possibleto improve the winding number of coil 11 b increases and the L value.When the outer diameter of magnet 30 a is smaller than the inner widthof coil 11 b (outer diameter of magnet 30 a is smaller than the innerwidth of coil 11 b by about 2 to 8 mm), it is possible to make magnet 30a not be provided between the facing portions of inner portions 211 and212, even though a variation exists in aligning precision. At this time,if the outer diameter of magnet 30 a is 70 to 95% of the inner width ofcoil 11 b, the variation in the aligning precision can be sufficientlyresolved, so that it is possible to improve aligning precision of theprimary-side non-contact charging module and the secondary-sidenon-contact charging module. The winding number of coil 11 b can besecured. This means that an area of magnet 30 a is 70 to 95% of an areaof the through-hole of the center of the planar coil portion, in asurface parallel to the planar coil portion. By this configuration, evenin a case where the aligning magnet is included in the other non-contactcharging module to be the counterpart of power transmission or a casewhere the magnet is not included, the change of the L value of theplanar coil in the non-contact charging module due to existence ornon-existence of the magnet decreases, so that it is possible to performaligning or power transmission. That is, secondary-side non-contactcharging module 2 can efficiently perform aligning with primary-sidenon-contact charging module 1 and power transmission, in both of thecase where magnet 30 a is included in primary-side non-contact chargingmodule 1 and the case where magnet 30 a is not included in primary-sidenon-contact charging module 1. In addition, primary-side non-contactcharging module 1 can efficiently perform aligning with secondary-sidenon-contact charging module 2 and power transmission, in both of thecase where magnet 30 b is included in secondary-side non-contactcharging module 2 and the case where magnet 30 b is not included insecondary-side non-contact charging module 2. Primary-side coil 11 aforms an LC resonance circuit with a resonance capacitor, inprimary-side non-contact charging module 1. At this time, if the Lvalues greatly change in the case where the magnet is used in aligningand the case where the magnet is not used in aligning, the resonancefrequency with the resonance capacitor may greatly change. Thisresonance frequency is used in power transmission of primary-sidenon-contact charging module 1 and secondary-side non-contact chargingmodule 2. For this reason, if the resonance frequency greatly changesaccording to existence or non-existence of the magnet, powertransmission may not be correctly performed. However, power transmissioncan be efficiently performed by the above configuration.

Furthermore, as illustrated in FIG. 9, when the size of magnet 30 a andthe outer diameter of secondary-side coil 11 b are constant, if theinner diameter of secondary-side coil 11 b is increased by decreasingthe winding number of secondary-side coil 11 b, an influence of magnet30 a with respect to secondary-side coil 11 b decreases. That is, the Lvalues of secondary-side coil 11 b in the case where magnet 30 a is usedin aligning of primary-side non-contact charging module 1 andsecondary-side non-contact charging module 2 and magnet 30 a is not usedbecome values similar to each other. Therefore, the resonance frequencyof when magnet 30 a is used and the resonance frequency of when magnet30 a is not used become very similar to each other. At this time, theouter diameter of the coil is set to 30 mm. The distance of the end ofthe hollow portion of primary-side coil 11 a and the outer end of magnet30 a is set to be larger than 0 mm and smaller than 6 mm, so that it ispossible to set the L values similar to each other, in the case wheremagnet 30 a is used and the case where magnet 30 a is not used, whilethe L values are maintained at 15 μH or more. The result of FIG. 9 isapplied to the L value of primary-side coil 11 a of primary-sidenon-contact charging module 1 in the case where magnet 30 b is includedin secondary-side non-contact charging module 2.

FIG. 10 is a schematic diagram illustrating a position relation of thenon-contact charging module according to the embodiment of the presentinvention and the magnet included in the other non-contact chargingmodule performing power transmission. In this case, the primary-sidenon-contact charging module includes the magnet that is used in aligningof the primary-side non-contact charging module and the secondary-sidenon-contact charging module. FIG. 10( a) illustrates the case where thesecondary-side coil has a rectangular shape and FIG. 10( b) illustratesthe case where the secondary-side coil has a circular shape. In thenon-contact charging module that is illustrated in these drawings, theexplanation where the concave portion or the through-hole that exists inthe hollow portion of the coil portion of the magnetic sheet will beomitted.

At this time, the relation of the magnet and the non-contact chargingmodule is applied to both a relation of primary-side non-contactcharging module 1 and magnet 30 b provided in secondary-side chargingmodule 2, and a relation of secondary-side non-contact charging module 2and magnet 30 a provided in primary-side non-contact charging module 1.Therefore, the relation of secondary-side non-contact charging module 2and magnet 30 a provided in primary-side non-contact charging module 1is described. However, the relation is applied to the relation ofprimary-side non-contact charging module 1 and magnet 30 b provided insecondary-side non-contact charging module 2. That is, a non-contactcharging module that can suppress an influence of the magnet included inthe other non-contact charging module that is the counterpart of powertransmission and perform aligning and power transmission in both of thecase where the magnet is included in the other non-contact chargingmodule and the case where the magnet is not included in the othernon-contact charging module will be described.

Secondary-side coil 11 c illustrated in FIG. 10( a) and secondary-sidecoil 11 b illustrated in FIG. 10( b) are positioned such that thecenters thereof are aligned with the center of aligning magnet 30 a. Inaddition, secondary-side non-contact charging module 2 may include themagnet, even when primary-side non-contact charging module 1 does notinclude magnet 30 a.

Aligning magnet 30 a that is included in the counterpart-sidenon-contact charging module has the diameter m and a circular shape, andmagnetic sheet 4 has a square shape. Magnetic sheet 4 may have apolygonal shape or a rectangular shape other than the square shape ormay have curved lines at corners. However, magnetic sheet 4 preferablyhas the square shape in order to decrease the size while securingperformance of primary-side non-contact charging module 1 that is thecounterpart side.

Since the standard of aligning magnet 30 a is suggested when non-contactcharging modules 1 and 2 are used, aligning magnet 30 a is used tosecure power transmission between non-contact charging modules 1 and 2and to align the transmission and reception coils.

When rectangular secondary-side coil 11 c and circular secondary-sidecoil 11 b having the same winding number are disposed on magnetic sheets4 having the same size, secondary-side coil 11 c and secondary-side coil11 b are stored in magnetic sheets 4 having the same area. That is, asillustrated in FIGS. 10( a) and 10(b), when rectangular secondary-sidecoil 11 c and circular secondary-side coil 11 b having the same windingnumber are disposed on magnetic sheets 4 having the length of one side,the shortest distance y1 between facing inner sides of rectangularsecondary-side coil 11 c and the inner diameter y2 of circularsecondary-side coil 11 b can be set to the same length.

Meanwhile, the length x of a diagonal line of the inner side ofrectangular secondary-side coil 11 c is longer than the shortestdistance y1 between the facing inner sides of rectangular secondary-sidecoil 11 b having the same length as the inner diameter y2 of circularsecondary-side coil 11 b. That is, in rectangular secondary-side coil 11c, an area increases where an interval of aligning magnet 30 a andsecondary-side coil 11 c is large, as compared with circularsecondary-side coil 11 b. That is, a relation of x>y1 and y1=y2 isrealized.

In order to suppress an influence of the magnet included in primary-sidenon-contact charging module 1 or secondary-side non-contact chargingmodule 2, the rectangular coil needs to satisfy a relation of x>=m,preferably, y1>=m.

If an interval of secondary-side coil 11 b or 11 c and aligning magnet30 a increases, an influence of aligning magnet 30 a decreases. For thisreason, a decrease ratio of the L value of secondary-side coil 11 b or11 c can be decreased. In the case where the secondary-side coil has arectangular shape, when the dimension x of the diagonal line of theinner side of secondary-side coil 11 c is equal to the dimension y2 ofthe inner diameter of circular secondary-side coil 11 b, a decreaseratio of the L value of secondary-side coil 11 c becomes substantiallyequal to a decrease ratio of the L value of secondary-side coil 11 b.

For this reason, when a space to store primary-side non-contact chargingmodule 1 of non-contact charger 400 has a square shape and the space islimited, it is preferable to form magnetic sheet 4 in a square shape andform secondary-side coil 11 c in a rectangular shape. Thereby, ascompared with the circular coil, rectangular secondary-side coil 11 ccan be apart from magnet 30 a and rectangular secondary-side coil 11 crarely receives an influence of magnet 30 a. The magnetic flux ofrectangular secondary-side coil 11 c is concentrated on the corners.However, since the distance of the corners and magnet 30 a is large, aninfluence of magnet 30 a can be decreased.

That is, when secondary-side coil 11 b is wound in a circular shape,entire secondary-side coil 11 b has almost the same strength of themagnetic flux. However, when secondary-side coil 11 b is wound in asubstantially rectangular shape, the magnetic flux is concentrated onthe corners. Therefore, if the dimension x of the diagonal line of theinner side of secondary-side coil 11 c is located outside of the outerdiameter of aligning magnet 30 a (x≧m), an influence of magnet 30 a canbe suppressed and power can be transmitted. If the shortest distance y1between facing inner sides of secondary-side coil 11 b is locatedoutside of the outer diameter of aligning magnet 30 a (y1≧m), entiresecondary-side coil 11 c is positioned outside than the outer diameterof aligning magnet 30 a and the corners of secondary-side coil 11 b arepositioned at the constant distance from magnet 30 a. Therefore, aninfluence of magnet 30 a with respect to secondary-side coil 11 b can bedecreased.

In the present embodiment, in order to satisfy the above-describedrelation, the dimension x of the diagonal line of rectangularsecondary-side coil 11 c is set to about 23 mm and the diameter m ofaligning magnet 30 a is set to 15.5 mmφ. Generally, aligning magnet 30 ais assumed to have the maximum diameter of 15.5 mm and configuredsmaller than the maximum diameter of 15.5 mm. When a small size andaligning precision are considered, aligning can be performed with a goodbalance by setting the diameter of magnet 30 a to about 10 to 15.5 mmand setting the thickness to about 1.5 to 2 mm. A neodymium magnet maybe used and the strength thereof may be about 75 to 150 mT. In thepresent embodiment, since an interval of the coil of the primary-sidenon-contact charging module and the coil of the secondary-sidenon-contact charging module is about 2 to 5 mm, it is possible toperform sufficient aligning by the corresponding magnet. Therefore, ifthe secondary-side coil is wound in a circular shape, the diameter ofthe hollow portion is set to 15.5 mm or more, and if the secondary-sidecoil is wound in a rectangular shape, the length of the diagonal line ofthe hollow portion is set to 15.5 min or more, preferably, the sidewidth of the hollow portion is set to 15.5 mm or more. As a result, aninfluence of magnet 30 a can be decreased, regardless of the size ofmagnet 30 a included in the counterpart side.

As described above, the rectangular coil is less influenced by themagnet than the magnet in the circular coil. However, if bothprimary-side coil 11 a and secondary-side coil 11 b described later arerectangular coils, the corners need to be aligned when charging andaligning are performed. Therefore, since angular adjustment at the timeof aligning is difficult, one coil may be a circular coil and the othercoil may be a rectangular coil. That is, this is because the angleadjustment does not need to be performed and the rectangular coil cansuppress an influence of the magnet. In addition, although one ofprimary-side non-contact charging module 1 and secondary-sidenon-contact charging module 2 may include the rectangular coil and theother may include the circular coil, since the circular coil mayefficiently perform power transmission without depending on a shape ofthe coil becoming the counterpart of power transmission, primary-sidenon-contact charging module 1 may include the circular coil.

In the rectangular coil, R (radius of the curved lines of the fourcorners) of angular portions of the four corners of the hollow portionis 30% or less of the side width (y1 of FIG. 10( a)) of the hollowportion, as compared with the circular coil. That is, in FIG. 10( a),the four corners of the hollow portion that has a substantiallyrectangular shape are configured in a curved shape. By configuring thefour corners to have the slightly curved lines, instead of the rightangle, it is possible to improve the strength of the electrical lines inthe four corners. However, if R excessively increases, the rectangularcoil is almost equal to the circular coil, so that it is not possible toobtain an effect that can be obtained only in the rectangular coil. As aresult of examination, when the side width y1 of the hollow portion is20 mm, if the radius R of the curved line of each corner is 6 mm orless, an influence of the magnet can be effectively suppressed. Asdescribed above, if the strength of the four corners is considered, theradius R of the curved line of each corner is 5 to 30% of the side widthof the hollow portion having the substantially rectangular shape, sothat it is possible to obtain an effect of the above rectangular coil.

Furthermore, a relation of the magnet and the hollow portion of the coilwound in a rectangular shape of the non-contact charging module will bedescribed.

FIG. 11 illustrates a decrease ratio of the L value of planar coilportion in the case where aligning magnet 30 a is included with respectto the case where aligning magnet 30 a is not included, when a dimensionof a diagonal line of the inner side of the rectangular planar coilportion of FIG. 10 and an inner diameter dimension of a circular planarcoil portion change (the size of magnetic sheet 4 is changed accordingto the dimension). That is, FIG. 11 illustrates a state in which aninfluence of the aligning magnet decreases as the decrease ratio of theL value decreases. In the present embodiment, the reception-sidenon-contact charging module is described as an example. However, it isobvious that the description of the reception-side non-contact chargingmodule can be applied to the transmission-side non-contact chargingmodule.

As illustrated in FIG. 11, as an internal dimension of the coilincreases, the decrease ratio of the L value of the planar coil portiondecreases. This is because the area where the interval of aligningmagnet 30 a and the inner side of the planar coil portion issufficiently taken increases and an influence of aligning magnet 30 adecreases. Meanwhile, when the dimension of the diagonal line of theinner side of the rectangular planar coil portion and the dimension ofthe inner diameter of the circular planar coil portion have the samevalue, the decrease ratio of the L value of the planar coil portion hasthe same value.

That is, if the dimension x of the diagonal line of the inner side ofthe rectangular planar coil portion and the dimension y of the innerdiameter of the circular planar coil portion are larger than thediameter in of the aligning magnet (x=y>m), a gap can be generatedbetween the inner side of the planar coil portion and the outer diameterof the aligning magnet. However, in this case, the area of a plane ofthe planar coil portion in the rectangular planar coil portion isnarrower than that in the circular planar coil portion. Therefore, thedimension of the diagonal line of the inner side of the rectangularplanar coil portion can be increased so as to match the size of magneticsheet 4. In this way, in the case where the planar coil portion isdisposed in magnetic sheet 4, as compared with the circular planar coilportion, the gap can be generated between the inner side of the planarcoil portion and the outer side of the aligning magnet, so that it ispossible to decrease an influence of the aligning magnet in therectangular planar coil portion. In the present embodiment, in order tosatisfy the above-described relation, the dimension x of the diagonalline of the rectangular planar coil portion is set to about 23 mm andthe diameter m of aligning magnet 4 is set to 15 mmφ.

Next, the magnitude of the magnetic field that is generated in therectangular planar coil portion will be described using FIG. 12. FIG.12( b) is a cross-sectional view taken along the line A-A′ of FIG. 12(a), and FIG. 12( c) is a cross-sectional view taken along the line B-B′of FIG. 12( a). In FIG. 12( b), the end of the aligning magnet and theinner end of the rectangular planar coil portion become close to eachother, and the magnetic field that is generated in the rectangularplanar coil portion is decreased by the influence of the magnetic fieldof the aligning magnet. Meanwhile, in FIG. 12( c), the end of thealigning magnet and the inner end of the rectangular planar coil portionare apart from each other, it becomes difficult to receive the influenceof the magnetic field of the aligning magnet, and then the magneticfield that is generated in the rectangular planar coil portionincreases. That is to say, in the circular planar coil portion, in anyplace of the circumference of the coil, the magnetic field that isgenerated in the circular planar coil portion is small, that is, the Lvalue of the circular planar coil portion is low, the L value affectingmutual inductance of electromagnetic induction, so that the powertransmission efficiency of the non-contact charging module decreases.Meanwhile, in the above rectangular planar coil portion, the generatedmagnetic field increases, that is, the L value of the rectangular planarcoil portion that affects the mutual inductance of the electromagneticinduction becomes larger than the L value of the circular planar coilportion, so that power transmission efficiency of the non-contactcharging module when the rectangular planar coil portion is used becomessuperior to power transmission efficiency when the circular planar coilportion is used.

Next, a result that is obtained by measuring the L value of the planarcoil portion by changing the ferrite thickness of magnetic sheet 4 inthe rectangular planar coil portion and the circular planar coil portionin FIG. 10 will be described.

FIG. 13 illustrates a result that is obtained by measuring the L valueof the planar coil portion by changing the ferrite thickness of magneticsheet 4. In this case, the L value is an inductance value of the planarcoil portion, and power transmission efficiency of the non-contactcharging module becomes high as the L value increases.

In order to satisfy power transmission performance of the non-contactcharging module, the L value of the coil needs to be 6 to 8 μH. However,when the aligning magnet is provided, an effect of increasing thestrength of the magnetic field of magnetic sheet 4 decreases due to theinfluence of the aligning magnet.

According to FIG. 13, when the aligning magnet is provided, the ferritethickness of magnetic sheet 4 needs to be 500 μm in order for thecircular planar coil portion to generate the L value of the coil of 6 to8 μH. As compared with the circular planar coil portion, the L value ofthe rectangular planar coil portion that has the same ferrite thicknessbecomes 12 μH (refer to the arrow A).

Under the condition in which the ferrite thickness and the area ofmagnetic sheet 4 are equal to each other, the L value of the rectangularplanar coil portion becomes larger than the L value of the circularplanar coil portion. Therefore, the magnetic field that is generated bythe rectangular planar coil portion increases and power transmissionefficiency of the non-contact charging module increases.

When the L value of the rectangular planar coil portion and the L valueof the circular planar coil portion are set to the same value, theferrite thickness of magnetic sheet 4 can be set to a small value in therectangular planar coil portion. That is, if the L value is set to 6 to8 μH as a target value, the ferrite thickness of magnetic sheet 4 of therectangular planar coil portion can be set to 300 μm (refer to the arrowB) and the ferrite thickness can be made thinner. Therefore, it ispossible to reduce the thickness of the non-contact charging module, sothat the small size can be easily achieved.

As such, the influence of the magnetic field of the aligning magnet canbe prevented by configuring the planar coil used by the non-contactcharging module in a rectangular shape and the size of the non-contactcharging module can be decreased by improving power transmissionefficiency of the non-contact charging module.

The wounding of the coil is not limited to in a rectangular shape andmay be in a square shape or a polygonal shape having R at the corners.That is, the shape of the coil may be a shape in which the entire coilis disposed on magnetic sheet 4 and a portion where the inner edge ofthe coil is apart from the outer edge of the aligning magnet increases.In particular, with the rectangular shape, the above-described effectcan be obtained and the rectangular coil can be easily formed.

In the present embodiment, the coil of the rectangular planar coilportion is described to be wound in a square shape. However, the shapeof the coil is not limited to in a square shape and may be in arectangular shape. That is, if at least a part of the four inner sidesof the coil is closer to the outer side than the outer circumference ofthe aligning magnet, the above-described effect can be obtained.

The aligning magnet does not need to be disposed in both thetransmission-side non-contact charging module and the reception-sidenon-contact charging module and may be disposed on one side. In thepresent embodiment, the case where the aligning magnet is in thenon-contact charging module to be the counterpart side rather than inthe non-contact charging module has been described. However, thedescription of the above case can be applied to the case where thealigning magnet is installed in the non-contact charging module not tobe the counterpart side.

The minimum dimension of the diagonal line of the rectangular coil(which is also called angular coil) of FIG. 11 is about 19 mm. When thedimension of the diagonal line is 19 mm, the distance of the facingsides of the hollow portion of the inner side of the rectangular coil isabout 13.5 mm. Therefore, in FIG. 11, when the dimension of the diagonalline of the rectangular coil is 19 mm, the aligning magnet having thediameter of 15.5 mm and the hollow portion of the inner side of therectangular coil are covered. That is, if the size of the hollow portionof the inner side of the rectangular planar coil portion is larger thanthe size of the aligning magnet, it is possible to decrease the decreaseratio of the L value.

As described above, an influence of the magnet in the rectangular coilis smaller than an influence of the magnet in the circular coil.However, if both the primary-side coil and the secondary-side coil arerectangular coils, the corners need to be aligned when charging andaligning are performed. Therefore, since angular adjustment at the timeof aligning is difficult, one coil may be a circular coil and the othercoil may be a rectangular coil. That is, the angle adjustment does notneed to be performed and the rectangular coil can suppress an influenceof the magnet. In addition, one of the primary-side non-contact chargingmodule and the secondary-side non-contact charging module may include arectangular coil and the other may include the circular coil. However,since the circular coil can perform efficient power transmissionregardless of a shape of the coil which is the counterpart of powertransmission, the primary-side non-contact charging module may includethe circular coil.

As described above, in the present invention, the non-contact chargingmodule where the size of the hollow portion of the inner side of theplanar coil portion is larger than the size of the magnet is configured.At this time, if the size of the hollow portion of the inner side of theplanar coil portion is more than the size of the magnet, this means thatthe magnet included in the transmission-side non-contact charging module(other non-contact charging module) does not overlap the hollow portionof the planar coil portion of the reception-side non-contact chargingmodule, when the transmission-side non-contact charging module and thereception-side non-contact charging module are aligned. That is, thismeans that the magnet included in the transmission-side non-contactcharging module does not protrude to the coil surface from the hollowportion of the reception-side non-contact charging module and is storedin the hollow portion, when the transmission-side non-contact chargingmodule and the reception-side non-contact charging module are viewedfrom the upper side.

INDUSTRIAL APPLICABILITY

According to the transmission-side non-contact charging module and thenon-contact charging apparatus using the same according to the presentinvention, the change of the L value of the coil that is provided in thenon-contact charging module can be suppressed in both of the case wherethe magnet of the counterpart-side non-contact charging module is usedin aligning of the primary-side non-contact charging module and thesecondary-side non-contact charging module and the case where the magnetis not used. Therefore, the transmission-side non-contact chargingmodule and the non-contact charging apparatus can be used in both of thecase where the magnet is used and the case where the magnet is not usedand can be used as a transmission-side charging apparatus when aportable terminal such as a mobile phone, a portable audio device, and aportable computer and a portable apparatus such as a digital camera anda video camera are charged.

REFERENCE SIGNS LIST

-   1 Primary-side non-contact charging module-   2 Secondary-side non-contact charging module-   3 Magnetic sheet (primary side)-   4 Magnetic sheet (secondary side)-   11 a Primary-side coil-   11 b Secondary-side coil-   22 a, 23 a Terminal (primary side)-   22 b, 23 b Terminal (secondary side)-   30 a Magnet (primary side)-   30 b Magnet (secondary side)-   31 a Flat portion (primary side)-   31 b Flat portion (secondary side)-   32 a Center portion (primary side)-   32 b Center portion (secondary side)-   33 a Linear concave portion (primary side)-   33 b Linear concave portion (secondary side)-   34 a Slit (primary side)-   34 b Slit (secondary side)

The invention claimed is:
 1. A non-contact charging module that performspower transmission by an electromagnetic induction with anothernon-contact charging module that comprises a first hole and that isallowed to align with the other non-contact charging module in either afirst case or a second case, the first case being a case where a magnetincluded within the first hole in the other non-contact charging moduleis used when alignment with the other non-contact charging module isperformed, the second case being a case where the magnet is not withinthe first hole and thereby not used when the alignment is performed, thenon-contact charging module comprising: a planar coil portion in which aconducting wire is wound in a substantially rectangular shape and thatcomprises a second hole of a predetermined size, the second hole beingprovided within an inner winding of the planar coil portion; and amagnetic sheet on which a coil surface of the planar coil portion isplaced and that faces the coil surface of the planar coil portion,wherein a length of a shortest distance between opposed inner sides of asubstantially rectangular hollow portion of the planar coil portion islonger than a diameter of the magnet, and the predetermined size of thesecond hole is greater than 15.5 mm.
 2. The non-contact charging moduleaccording to claim 1, wherein a shape of the magnetic sheet issubstantially rectangular and the magnetic sheet has a concave portionor slit that extends toward an edge of the magnetic sheet.
 3. Anon-contact charging module apparatus using the non-contact chargingmodule according to claim 1 as at least one of a power transmissionmodule or a power reception module.
 4. The non-contact charging moduleaccording to claim 1, further comprising an alignment magnet, whereinthe alignment magnet couples to the magnet included in the othernon-contact charging module and the alignment magnet is used to alignthe non-contact charging module with the other non-contact chargingmodule.
 5. The non-contact charging module according to claim 4, whereina first area of the first hole is greater than a second area of thealignment magnet.
 6. The transmission-side non-contact charging moduleaccording to claim 5, wherein a first area of the first hole is greaterthan a second area of the alignment magnet.
 7. The non-contact chargingmodule according to claim 1, further comprising an alignment module,wherein the alignment module comprises an alignment unit to structurallyalign the non-contact charging module with the other non-contactcharging module.
 8. The non-contact charging module according to claim1, wherein the planar coil portion further comprises a coil surface andthe magnetic sheet is coupled opposite to the coil surface.
 9. Thenon-contact charging module according to claim 8, wherein the magneticsheet touches the coil surface.
 10. The non-contact charging moduleaccording to claim 1, wherein the substantially rectangular hollowportion is formed at an inner position corresponding to the innerwinding of the planar coil portion.
 11. The noncontact charging moduleaccording to claim 1, wherein a first area of the second hole is greaterthan a second area of the magnet.
 12. A transmission-side non-contactcharging module that transmits power to a reception-side non-contactcharging module that comprises a first hole by an electromagneticinduction and that is allowed to align with the reception-sidenon-contact charging module in either a first case or a second case, thefirst case being a case where a magnet included within the first hole inthe reception-side non-contact charging module is used when alignmentwith the reception-side non-contact charging module is performed, thesecond case being a case where the magnet is not within the first holeand thereby not used when the alignment is performed, thetransmission-side non-contact charging module comprising: a planar coilportion in which a conducting wire is wound and that comprises a secondhole of a predetermined size, the second hole being provided within aninner winding of the planar coil portion; and a ferrite sheet on which acoil surface of the planar coil portion is placed and that faces thecoil surface of the planar coil portion and that attracts, in the casewhere the magnet is used when the alignment with the reception-sidenon-contact charging module is performed, the magnet of thereception-side non-contact charging module, wherein the predeterminedsize of the second hole is larger than a size of the magnet included inthe reception-side non-contact charging module, and wherein thepredetermined size of the second hole is greater than 15.5 mm.
 13. Thetransmission-side non-contact charging module according to claim 12,wherein a distance between an edge of a hollow portion of the planarcoil portion and an outer edge of the magnet is more than 0 mm andsmaller than 6 mm.
 14. The transmission-side non-contact charging moduleaccording to claim 12, wherein the planar coil portion is configuredsuch that an area of the magnet becomes 80 to 95% of area of the innerwinding of the planar coil portion, in a surface parallel to the planarcoil portion.
 15. A transmission-side non-contact charging apparatuscomprising a transmission-side non-contact charging module according toclaim 12, the transmission-side non-contact charging module comprising:a planar coil portion in which a conducting wire is wound in a spiralshape and comprises a second hole of a predetermined size, the secondhole being provided within an inner winding of the planar coil portion;a terminal that supplies a current from an external power supply to theplanar coil portion; and a magnetic sheet that places a coil surface ofthe planar coil portion and faces the coil surface of the planar coilportion, wherein the predetermined size of the second hole is at leastequal to a size of the first hole in the reception-side non-contactcharging module, and the predetermined size of the second hole isgreater than 15.5 mm.
 16. The transmission-side non-contact chargingmodule according to claim 12, wherein the ferrite sheet is magneticallycoupled to an alignment magnet of the reception-side non-contactcharging module.
 17. The transmission-side non-contact charging moduleaccording to claim 16, wherein the planar coil portion is configuredsuch that an area of the alignment magnet becomes 80 to 95% of n area ofthe inner winding of the planar coil portion, in a surface parallel tothe planar coil portion.
 18. The transmission-side non-contact chargingmodule according to claim 12, wherein the transmission-side non-contactcharging module is structurally coupled to the reception-sidenon-contact charging module.
 19. The transmission-side non-contactcharging module according to claim 12, wherein a first area of thesecond hole is greater than a second area of the magnet.
 20. Areception-side non-contact charging module that receives power from atransmission-side non-contact charging module that comprises a firsthole by an electromagnetic induction and that is allowed to align withthe transmission-side non-contact charging module in either a first caseor a second case, the first case being a case where a magnet includedwithin the first hole in the transmission-side non-contact chargingmodule is used when alignment with the transmission-side non-contactcharging module is performed, the second case being a case where themagnet is not within the first hole and thereby not used when thealignment is performed, the reception-side contact charging modulecomprising: a planar coil portion in which a conducting wire is wound ina spiral shape and comprises a second hole of a predetermined size, thesecond hole being provided within an inner winding of the planar coilportion; and a magnetic sheet on which a coil surface of the planar coilportion is placed and that faces the coil surface of the planar coilportion and that attracts, in the case where the magnet is used when thealignment with the transmission-side non-contact charging module isperformed, the magnet of the transmission-side non-contact chargingmodule, wherein an inner diameter of the planar coil portion is largerthan the magnet included in the transmission-side non-contact chargingmodule, and the predetermined size of the second hole is greater than15.5 mm.
 21. The reception-side non-contact charging module according toclaim 20, wherein a distance between an edge of the inner diameter ofthe planar coil portion and an outer edge of the magnet is more than 0mm and smaller than 6 mm.
 22. The reception-side non-contact chargingmodule according to claim 20, wherein the planar coil portion isconfigured such that an area of the magnet becomes 80 to 95% of area ofthe inner winding of the planar coil portion, in a surface parallel tothe planar coil portion.
 23. A reception-side non-contact chargingapparatus, comprising the reception-side non-contact charging moduleaccording to claim 20, that receives power from a transmission-sidenon-contact charging apparatus comprising the transmission-sidenon-contact charging module.
 24. The reception-side non-contact chargingmodule according to claim 20, further comprising an alignment magnet,wherein the alignment magnet couples to the magnet included in thetransmission-side non-contact charging module and the alignment magnetis used to align the reception-side non-contact charging module with thetransmission-side non-contact charging module.
 25. The reception-sidenon-contact charging module according to claim 24, wherein a first areaof the first hole is greater than a second area of the alignment magnet.26. The reception-side non-contact charging module according to claim24, wherein the planar coil portion is configured such that an area ofthe alignment magnet becomes 80 to 95% of an area of the inner windingof the planar coil portion, in a surface parallel to the planar coilportion.
 27. The reception-side non-contact charging module according toclaim 24, wherein the alignment magnet has a circular shape and adiameter of the alignment magnet is 15.5 mm.
 28. The reception-sidenon-contact charging module according to claim 20, further comprising analignment module, wherein the alignment module comprises an alignmentunit to structurally align the reception-side non-contact chargingmodule with the transmission-side non-contact charging module.
 29. Thereception-side non-contact charging module according to claim 20,wherein a first area of the second hole is greater than a second area ofthe magnet.
 30. A non-contact charging module that performs powertransmission by an electromagnetic induction with another non-contactcharging module that comprises a first hole and that is allowed to alignwith the other non-contact charging module in either a first case or asecond case, the first case being a case where a magnet included withinthe first hole in the other non-contact charging module is used whenalignment with the other non-contact charging module is performed, thesecond case being a case where the magnet is not within the first holeand thereby not used when the alignment is performed, the non-contactcharging module comprising: a planar coil portion in which a conductingwire is wound in a substantially rectangular shape and that comprises asecond hole of a predetermined size, the second hole being providedwithin an inner winding of the planar coil portion; and a magnetic sheeton which a coil surface of the planar coil portion is placed and thatfaces the coil surface of the planar coil portion, wherein thepredetermined size of the second hole is at least equal to a size of thefirst hole, and the predetermined size of the second hole is greaterthan 15.5 mm.
 31. A reception-side non-contact charging module thatreceives power from a transmission-side non-contact charging module thatcomprises a first hole by an electromagnetic induction and that isallowed to align with the transmission-side non-contact charging modulein either a first case or a second case, the first case being a casewhere a magnet included within the first hole in the transmission-sidenon-contact charging module is used when alignment with thetransmission-side non-contact charging module is performed, the secondcase being a case where the magnet is not within the first hole andthereby not used when the alignment is performed, the reception-sidecontact charging module comprising: a planar coil portion in which aconducting wire is wound in a spiral shape and comprises a second holeof a predetermined size, the second hole being provided within an innerwinding of the planar coil portion; and a magnetic sheet on which a coilsurface of the planar coil portion is placed and that faces the coilsurface of the planar coil portion and that attracts, in the case wherethe magnet is used when the alignment with the transmission-sidenon-contact charging module is performed, the magnet of thetransmission-side non-contact charging module, wherein the predeterminedsize of the second hole is at least equal to a size of the first hole,and the predetermined size of the second hole is greater than 15.5 mm.